No clue. And besides, I highly doubt he'd make info like that public knowledge, I mean, it's not like he'd want to be harrassed by fangirls all the time.
a) Celebrities don't have facebook. It's either twitter or something else new and supposedly "different" from the old social site.
b) He'd never display his email, but I can guess that it would be an email address you'd have to pay for (i.e. aol)
